System and method for testing diffusion ability of chloride ions in concrete under bending load effect

Abstract

The invention discloses a system for testing diffusion ability of chloride ions in concrete under a bending load effect. The system comprises a bending load loading device and an electric-accelerationrapid chloride ion migration device, wherein the bending load loading device mainly consists of a steel base plate, a hollow steel plate (3), a hydraulic jack I (1) and a hydraulic jack II (2); and the electric-acceleration rapid chloride ion migration device mainly consists of an anode test tank (16), a cathode test tank (17) and a circular water storage tank. On the basis, a relational model among the hollow steel plate size, the steel material size, the still base plate thickness, the jack height and the jack bearing capacity researched, so that theoretical basis is provided by the inventors for the design of the bending load loading device. Hereby, the inventors establish a corresponding test method; the test method is used for testing the diffusion ability of chloride ions in concrete under a continuous bending load effect by utilizing the test system; and by combining a DIC image processing technology, the method can be used for the relationship between stress and chloride ion diffusion coefficients.

Description

technical field [0001] The invention belongs to the technical field of concrete chloride ion migration coefficient measurement, in particular to a concrete chloride ion diffusion performance test system and method thereof under bending load. Background technique [0002] There are many reasons for the corrosion of steel bars, and the corrosion of steel bars caused by chloride ion depassivation is the most common and serious, and the corrosion of steel bars is an important factor that causes the damage of concrete structures. In the actual environment, concrete structures are often subject to the coupling effect of load and chloride ions, so the study of the permeability of chloride ions under load is of great significance to the engineering safety of concrete. At present, a lot of research has been done on the determination methods of the chloride ion penetration resistance of concrete structures at home and abroad, and relevant experimental procedures have been formulated. ...

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Problems solved by technology

However, these two experimental methods cannot realize the application of various loads at the same time as the test. In actual situations, concrete specimens are often subject to coupling effects of loads and various environmental factors, and the volume and shape of capillary pores in the cement slurry will be affected after unloading. , and the permeability of concrete largely depends on the volume and shape of the interconnected capillary pores in the cement slurry, so the continuity of the load will affect the transmission and diffusion of chloride ions inside the concrete structure, that is, the permeability of chloride ions

[0003] The Chinese patent "Concrete Chloride Ion Migration Coefficient Loading Test Device and Testing Method Under Bending Stress" (Patent No. 201210012423.6 Publication Date 20120801) discloses a concrete chloride ion migration coefficient loading testing device and testing method under continuous bending stress; however The experimental device maintains the pressure on the concrete specimen through the tension screw. When the test time is long, the pressure decreases due to the creep of the concrete specimen, and the research is on the chloride ion permeability of concrete under bending load. Investigate the bending load

[0004] Chinese patent application "Concrete Rapid Chloride Ion Transfer Coefficient Loading Test Device and Its Method" (Application No. 201210013077.3 Publication Date 20120711) discloses a concrete rapid chloride ion transfer coefficient loading test device and its method under uniaxial continuous pressure load. The load on the tested piece is applied and maintained by the jack and the tension screw, and the experimental device cannot also apply a compressive bending load to the tested piece

[0005] To sum up, the current test device and method for testing the chloride ion diffusion performance of concrete under the action of continuous bending load using the principle of rapid chloride ion migration are still blank in China.

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